The use of 3D-laser scanning in assessing the safety of masonry vaults—A case study on the church of Saint-Jacobs (original) (raw)
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2021
Terrestrial laser-scanning (TLS) is well suited to surveying the geometry of monumental complexes, often realised with highly irregular materials and forms. This paper addresses various issues related to the acquisition of point clouds via TLS and their elaboration aimed at developing structural models of masonry vaults. This structural system, which exists in numerous artifacts and historical buildings, has the advantages of good static and functional behaviour, reduced weight, good requisites of insulation, and aesthetic quality. Specifically, using TLS, we create a geometric model of the ancient masonry church, S. Maria della Libera, in Aquino, largely characterised by naves featuring cross vaults and previously used as a case study in the paper entitled ‘Terrestrial laser-scanning point-clouds for modeling masonry vaults’, presented at the 2019 IMEKO TC-4 International Conference on Metrology for Archaeology and Cultural Heritage. The results of the TLS survey are used as input ...
Journal of Cultural Heritage, 2014
Restoring cultural heritage is an extremely important job due to its immeasurable value. However, it also requires even greater attention in the case of a building. The actions taken on these constructions not only guarantee their preservation from the point of view of their historical value, but they also guarantee their stability as structures. The need to control historic buildings, analyzing their defects and their possible consequences, is decisive in preventing significant damage. This work demonstrates calculating the thickness of vaults in a church. It is easy to determine the interior and exterior 3D geometry of the church using scanner laser techniques. By combining both geometries, it is easy to determine the difference between the interior vaults and the roof of the church. However, the interior of both geometries is completely unknown, and it is not possible to act on their condition for structural consolidation purposes. This work shows the methods used to determine the interior sections of the vault thicknesses by referencing the internal geometry of both models with the interior of the church, using plumb line system scanning. The results obtained show accuracy better than 6 millimeters.
The 3D laser scanner has become a common instrument in numerous field applications such as structural health monitoring, assessment and documentation of structural damages, volume and dimension control of excavations, geometrical recording of built environment, and construction progress monitoring in different fields. It enables capture of millions of points from the surface of objects with high accuracy and in a very short time. These points can be employed to extrapolate the shape of the elements. In this way, the collected data can be developed to construct three-dimensional digital models that can be used in structural FEM analysis. This paper presents structural evaluation of a historic building through FE models with the help of a 3D point cloud. The main focus of the study is on the stone columns of a historic cistern. These deteriorated load bearing elements have severe non-uniform erosion, which leads to formation of significant stress concentrations. At this point, the 3D geometric data becomes crucial in revealing the stress distribution of severely eroded columns due to material deterioration. According to the results of static analysis using real geometry, maximum stress in compression increased remarkably on the columns in comparison with the geometrically idealized models. These values seem to approach the compressive strength of the material, which was obtained from the point load test results. Moreover, the stress distribution of the analysis draws attention to the section between columns and their capitals. According to the detailed 3D documentation, there is a reduced contact surface between columns and capitals to transfer loads.
Proceedings of the 6th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015), 2017
The technology of high-definition laser scanning is an essential tool for accurate non-destructive three-dimensional measurements of structures. The object's geometry is captured as a collection of points which is called a "point cloud". The research team used this technology and conducted an extensive laser scanning program of many historic monuments in Uzbekistan. The program started in 2013 from scanning the famous Registan ensemble in Samarkand. Later in 2015, it was expanded to more cities and monuments and the laser scanning was conducted in Tashkent, Bukhara, Samarkand and Shakhrisyabz. The scanned monuments are from the Timurid Dynasty era and they are on the UNESCO World Heritage List. This paper summarizes some results of this extensive ongoing program. As a representative example, the research results based on data obtained in Shakhrisabz (Uzbekistan) are discussed in details. The city is located in southern Uzbekistan approximately 80 km south of Samarkand, Uzbekistan. Once a major city of Central Asia, it is primarily known today as the birthplace of 14th century Turco-Mongol conqueror Timur. The Kok Gumbaz (Blue Dome) Mosque was built in 1437 and underwent several restorations and reinforcement efforts. A detailed finite element model of the monument was generated from the as-found geometry captured by laser scans. To monitor the buildings' possible settlement due to poor soil conditions, special high-resolution laser targets were permanently installed. The physical properties of the monuments were investigated by material tests of the major components recovered from the historic sites. The calibrated models were used for comprehensive seismic analysis
Applied Sciences
This research presents a new intervention methodology on arches and vaults of a Renaissance factory in the Colegio Santo Domingo de Orihuela (16th century) using 3D software LIDAR technology that verifies the execution process of the works studying the different charges states and structure behavior. This document aims to explain a working methodology in the monitoring of structural repair interventions in the architectural heritage, in the specific case of the replacement of traditional one-way timber joist frame slabs on structures of former, splay and groin arches between vaults. This involves the compilation and processing of two types of data: on the one hand, the analysis of the different load states to which the intervention is exposed in its different phases: initial, dismantling of the different layers of traditional construction and replacement by the new structural system; and, on the other hand, the graphic information provided by the photogrammetry techniques used to di...
Terrestrial Laser Scanning and Non Parametric Methods in Masonry Arches Inspection
Historical bridges are not only elements of our cultural heritage but also civil engineering structures. They are usually researched with destructive technologies, but their geometry is being more and more used in order to perform structural analysis, and this way it would be possible to make a diagnosis of their state of conservation. Laser scanners collect a great amount of data that allows building accurate 3D models that can be then used to make dimensional and structural analysis of these civil structures. This paper presents a geometrical research carried out in the Roman Bridge of Segura (Spain). A 3D model of the bridge was built by means of a terrestrial laser scanner, and then its geometry was analyzed by two different methods. Firstly, by means of a direct way, a graphical analysis in CAD systems was performed and the main geometrical parameters were obtained and evaluated; secondly, using statistical nonparametric methods, developed for this kind of structures, it was possible to identify pathologies on the structure thanks to the measurement of deformations in vaults by means of a symmetrical study. The results of both methods are presented in this work, and then they are compared and discussed.
Numerical Analysis of Historic Structural Elements Using 3D Point Cloud Data
The Open Construction and Building Technology Journal, 2016
The 3D laser scanner has become a common instrument in numerous field applications such as structural health monitoring, assessment and documentation of structural damages, volume and dimension control of excavations, geometrical recording of built environment, and construction progress monitoring in different fields. It enables capture of millions of points from the surface of objects with high accuracy and in a very short time. These points can be employed to extrapolate the shape of the elements. In this way, the collected data can be developed to construct three-dimensional digital models that can be used in structural FEM analysis. This paper presents structural evaluation of a historic building through FE models with the help of a 3D point cloud. The main focus of the study is on the stone columns of a historic cistern. These deteriorated load bearing elements have severe non-uniform erosion, which leads to formation of significant stress concentrations. At this point, the 3D ...